1. Field of Invention
The invention relates to a control system for an optical storage device, and more particularly to a control system for determining read performance of an optical storage device according to lock performance of a re-timing signal.
2. Related Art
In a typical digital versatile disk (DVD) product, a method of adjusting a servo system parameter is to count the number of errors of an error correction code (ECC). When the number of the ECC errors is great, a servo system has to try another set of parameters and then count the number of the ECC errors again.
FIG. 1 shows the architecture of a conventional control system for an optical storage device. Referring to FIG. 1, the control system 10 for the optical storage device includes an optical pickup 12, a servo control unit 13, a filtering and re-timing unit 14, an error correction unit 15 and a servo control loop 16. The optical pickup 12 reads a signal of an optical disc 11 and then generates a radio frequency (RF) signal. The filtering and re-timing unit 14 reads the RF signal and generates an un-corrected output signal. The error correction unit 15 reads the un-corrected output signal and then corrects an error bit in an error control code block of a data block memory cell according to a Reed-Solomon (RS) algorithm to generate a corrected output signal. When the error correction unit 15 is correcting the data, it also counts the number of errors and outputs an error counting value. The servo control loop 16 receives the error counting value and the RF signal associated with a servo, and outputs a servo control signal. The servo control unit 13 receives the servo control signal and controls operations of a spindle motor and the optical pickup 12.
When the number of the ECC errors (the error counting value) is great, the servo control loop 16 has to try another set of parameters to count the number of the ECC errors again. Because the time for counting the number of the ECC errors is longer, the time for the overall procedure of adjusting the servo system parameters is longer.